Integrated circuits may be damaged from discharges of static electricity, even at levels which can neither be seen nor felt. This is typically referred to as electrostatic discharge (ESD), where a transfer of an electrostatic charge occurs between bodies at different electrostatic voltage potentials caused by direct contact or induced by an electrostatic field. Circuit failures due to ESD are not always immediately catastrophic, but often a circuit is weakened, is less able to withstand normal operating stresses, and thus, may result in a reliability problem.
Various ESD protection circuits have been included in integrated circuits to protect various components, with an assortment of considerations necessary for such ESD protection circuits. For example, ESD protection is necessary for all pins going to the outside world. However, some ESD protection circuits are not robust since they, for instance, cannot handle ESD's of negative voltage potentials. In addition, other ESD protection circuits require large areas of integrated circuits, resulting in less capacity for functional paths in integrated circuits.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.